78 CB750F - The story of my first build

[rrredisk]

I bought a 1978 cb750f a few weeks ago, and just got the funds to start my cafe project on it. Tonight i just ordered my new exhuast, front brakes, new throttle and clutch cables, and a few other parts. Currently I got the bike running, but it is a rough running, so it still needs some work with the carbs and such. All my parts are supposed to be getting in next week sometime so I have a lot of work ahead of me putting everything on the bike.

 

[BCBarker]

Re: 78 CB750F getting ready for a cafe upgrade

HAHA! I almost bought that! Where are you? I'm in richmond.

Nice score!

B

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

HAHA! I almost bought that! Where are you? I'm in richmond.

Nice score!

B

Haha. I live in Raleigh, drove 4 hours to go pick up the bike. Lucky you didn't get that, then i wouldn't be able to start my little project, haha!

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

Painted some parts this weekend. The swing arm, rear shocks, sprocket, and a few brackets all got a fancy new gloss black finish.

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/z1j46ZFFi-EfmJZ1EmvmKA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/TF9oYEhtC_I/AAAAAAAAALA/RzDj35mV-RA/s144/2010-08-08%2018.46.28.jpg" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/rrredisk/Bike?feat=embedwebsite">Bike</a></td></tr></table>

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All my parts were ordered the other night and should be coming some time this week from various places. Should be a great week, kinda like Christmas in August!

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

So today I was going to flip the headlight brackets to lower the headlights so i could then lower gauges. I flipped and cut the headlight brackets, but i got carried away and decided to fab up a whole new gauge cluster bracket. I am going to mount all my electronic buttons and switches on my gauge cluster, such as the start button, turn signals, run/off switch, horn, and lights switch, so I laid them out nicely in between the gauges on the new mount bracket. This means on my bars I will only have my grips and levers, no electrical controls.

Here is a pic of the headlight bracket flipped and trimmed down.
<a href="http://picasaweb.google.com/lh/photo/FGrwz7mocxVaSJu6pX7H_g?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/TGC8yYgCgYI/AAAAAAAAALc/3O-z_omUtKA/s400/2010-08-09%2015.05.41.jpg" /></a>

The pattern for the new gauge bracket. I drew it all up on paper first so I could get measurements correct.
<a href="http://picasaweb.google.com/lh/photo/z3LIs9yn6Npgt2-oGnKv4g?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/TGC8jr8xmMI/AAAAAAAAALY/Amn2TEQ3HLU/s400/2010-08-09%2020.08.20.jpg" /></a>

I used a Dremel with some cuttoff wheels to cut out a rough outline of the bracket.
<a href="http://picasaweb.google.com/lh/photo/GX-rfp-fDQ2j-bA7doCJoQ?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TGC8bjhjYyI/AAAAAAAAALU/wB473P5wzG4/s400/2010-08-09%2021.45.56.jpg" /></a>

Here is the bracket with the gauges mounted on it. The holes were a little to small to put the switches in, and the neighbor was complaining i was being to loud with the tools, so i gotta wait until tomorrow to drill out the holes a little more. The two little holes in the middle under the turn signal switch hole are going to be a red led light for oil and a green led light for a neutral light.
<a href="http://picasaweb.google.com/lh/photo/133_U6Vqig4GsSYLYZsFrA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/TGDB1_H9III/AAAAAAAAALs/0XWXf4wUqZ4/s400/2010-08-09%2022.36.39.jpg" /></a>

Hopefully tomorrow I can get it it painted black and the switches all mounted in it so I can then work on wiring everything together. Should be fun!

 

[jay_kent]

Re: 78 CB750F getting ready for a cafe upgrade

Is the space between the gauges so large to fit the headlight between them? Right no IMO, it's too much space between those guys. See what it looks like on but I'm not feeling it yet.

Remember it's only one man's opinion.

The flipped headlight ears look good though.

Jay

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

Is the space between the gauges so large to fit the headlight between them? Right no IMO, it's too much space between those guys. See what it looks like on but I'm not feeling it yet.

Remember it's only one man's opinion.

The flipped headlight ears look good though.

Jay

The gap isnt big enough for the light to fit, but i am going to lower the bracket so it sits right above the headlight, almost partially in between the gauges, but not fully. I never thought about putting the headlight between the gauges though, those stock gauges are just so dang big that i feel like it may be to wide of an assembly like that.

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

Finished grinding, painting and mounting the new gauge bracket today. also soldered up all the new switches, no tomorrow I get to try and wire the whole bike back together, should be fun :/

All the switches soldered and heat shrunk wrapped.
<a href="http://picasaweb.google.com/lh/photo/Xce4pUpMG6z3e-wx8L9d-g?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TGH5gpxyXgI/AAAAAAAAAL0/sF_f-J68GVo/s400/2010-08-10%2020.07.23.jpg" /></a>

Here is the bracket mounted with the switches and gauges attached to it.
<a href="http://picasaweb.google.com/lh/photo/xIahI1LtE5fhM0AKlW1Kag?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/TGH5sHtGDoI/AAAAAAAAAL4/83vs7kTlqS4/s400/2010-08-10%2021.02.21.jpg" /></a>

Now I get to attempt to make the underside of the bracket with all the wires look a little more "clean"
<a href="http://picasaweb.google.com/lh/photo/wN79I1B2MXHg_qtMdB1Tow?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/TGH6v26Oq7I/AAAAAAAAAMI/hCkIMAdEQ1o/s400/2010-08-10%2021.02.47.jpg" /></a>

 

[TheHead]

Re: 78 CB750F getting ready for a cafe upgrade

Now I get to attempt to make the underside of the bracket with all the wires look a little more "clean"
<a href="http://picasaweb.google.com/lh/photo/wN79I1B2MXHg_qtMdB1Tow?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/TGH6v26Oq7I/AAAAAAAAAMI/hCkIMAdEQ1o/s400/2010-08-10%2021.02.47.jpg" /></a>

That's looking really good. It's inspiring to see this because I want to dive into cleaning up the gauges of my bike and slim down the controls like you're doing; being a newbie, it's nice to have some examples to go off of. Keep up the good work.


Head

 

[mysta2]

Re: 78 CB750F getting ready for a cafe upgrade

I like how you did the "dash" the spacing does seem a bit wide though... to me.

I have to suggest looking into some multi pin connectors: (click on any of these)




one of my personal favorites:

I wired my truck with these.




stock-ish looking:


or you can go full on mil-spec:

These are nice when passing through bulkheads.

Run your' wire lengths a little longer, bin the bullet connectors and put a couple multipin connectors in a nice hidden away spot. Make sure to match your colors up and you can't go wrong.

 

[rrredisk]

Re: 78 CB750F getting ready for a cafe upgrade

So a decent bit of work has been done to the bike in the last few weeks, but it is a slow process now that I started work back up. Hopefully by this weekend I can get her running with the new exhaust and work on tuning the carbs.

Here is the seat that I upholstered myself. I cut out come sections of vinyl fabric and sewed them together. For my first time sewing with a needle and thread by hand, i think i did a pretty good job I then attached the fabric to the seat with some button snaps from the hardware store. then i made a frame out of aluminum square tubing that the seat could sit on and be mounted to the bike frame with.
<a href="http://picasaweb.google.com/lh/photo/JsLgxiwJAi1vJF5p1qPD4w?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/THux-srzN5I/AAAAAAAAAMs/G_KuywI8qQM/s400/IMG_20100816_203925.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/t1hKazv8gEr2pxyNyYgyFA?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/THuyweFqFOI/AAAAAAAAANQ/einHlNPMka4/s400/IMG_20100829_155449.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/TXP0nOkKStmbM0oYPYDobA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/THuywmUbfuI/AAAAAAAAANU/MH9TDJbHEMg/s400/IMG_20100829_155509.jpg" /></a>

I broke down and ordered new gauges, the stock ones looked way to goofy as big as they were and as wide set as i had them. Also when i put on the handlebars with the brake lever on there, it was hitting the gauges and not leaving me enough for the throttle part on the end, so it was sort of a necessity i guess.
<a href="http://picasaweb.google.com/lh/photo/svL3R_ieOBdxVutN-KkZKg?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/THux_gCsQ8I/AAAAAAAAAM0/wmXsSUbh9h4/s400/IMG_20100829_155041.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/36JNEr81XRlBvycp0N_tKg?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/THuyAM0DGfI/AAAAAAAAAM4/asGar2s6Ks0/s400/IMG_20100829_155052.jpg" /></a>

When i got the bike it was missing the left side cover, so i figured i would try my luck at fab'ing up some side covers out of some sheet metal. I took some measurements and then made them in solid works so i could get the correct angles, then printed off the flat pattern, traced it onto the sheet metal and went to cutting and bending. They turned out pretty good, I need to trim the top off of them so it sits better up against the seat but i think they will work just fine in the end.
<a href="http://picasaweb.google.com/lh/photo/eUvF9VjZtfxJGTM3rlib1A?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/THuyvVKDedI/AAAAAAAAANI/LmsiC0BBJNc/s400/IMG_20100829_155314.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/iT-7QILoEwYUc_DWmYs4uA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/THuyvqkDM1I/AAAAAAAAANM/OubWVdju7hI/s400/IMG_20100829_155328.jpg" /></a>

I also chopped up the front fender a little bit so it looked a little more sleek and stylish.
<a href="http://picasaweb.google.com/lh/photo/P-0szv4OOn064D5LHPocFw?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/THuyu9_TCWI/AAAAAAAAANE/z7FV7GIV1T0/s400/IMG_20100829_155214.jpg" /></a>

Here she is prior to stripping the tank and prepping it for paint. she still needs a good bit of work and a proper paint job. I bought some rearsets off ebay a couple days ago so I need to work on figuring out how I am going to mount them. I have the rear turn signals and tail light that i need to figure out how/where to mount too. I need to mount the front brakes back on as well. I bought some dual piston ones off of a cb900f since the bike was missing the front right caliper when i bought it, and the cb900f ones mount up perfectly. I am going to buy a new rear tire because the one that I just got looks way to goofy on the bike. i went with what size bikebandit had for the stock rear tire, and it is super skinny, so I am going to order a 130/90 this week so it looks a little better on the bike. I also need to order a new front tube for the tire. The new one i just put in it was instantly flat. I probably pinched it while putting the tire on, which stinks b/c those tires were a pain in the butt to get on those wheels.
<a href="http://picasaweb.google.com/lh/photo/r6xUF_iV9T2epblqT52Oeg?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/THux_CMP3gI/AAAAAAAAAMw/55vU4l-fILU/s400/IMG_20100828_105025.jpg" /></a>

 

[rrredisk]

After the long weekend, the bike is getting real close to a ridable/almost finished condition. I spent the evening last week painting my tank and seat. It was a long process of spraying a few layers, letting it dry, then wetsanding. Overall I think it turned out pretty good for it being a rattle can job and being done outside on the sidewalk. I also installed my new front brakes that are from a CB900f with dual pistons rather than the single ones in the stock brakes. I got my turn signals and brake lights mounted onto the back of the seat. Then it was on to the big part of the project, the rearsets... For the right side I cut the big plate that holds the passenger foot pegs. exhaust, brake lever and other stuff, and then drilled holes into it to bolt on the rearset. I still need to get the new master cylinder mounted and find a way to get the brake switch to mount as well. On the left side it wasnt as easy because the plate is a lot smaller than the right side. i ended up having to cut notches into the plate and basically clamp the rearset to the plate as seen in the pictures below. The left rearset feels like it stick out from the bike a little more than the right, so I may need to do some trimming, but for now they are on there nicely enough to ride around with. All i really have left as far as big things go is figuring out a few electrical gremlins with my turn signals, and then just tuning the bike so it runs smoothly. I am so close i can taste it...


Here is the seat and tank that I painted, not professional quality up close, but they look great from about 10 feet away.
<a href="http://picasaweb.google.com/lh/photo/d8EDpLc-bDdiCaahXwoocA?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TIZelGT3oNI/AAAAAAAAAOU/Sg15FUlvsMQ/s400/IMG_20100901_233848.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/sphKBb4dBRe3KRT1KZiuDw?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TIZek9jExfI/AAAAAAAAAOQ/KhqA_AVzpMQ/s400/IMG_20100903_070132.jpg" /></a>

Here is the right side rearset. the master cylinder still needs to be mounted up somewhere and i need to get a little longer brake line before it will be ride ready.
<a href="http://picasaweb.google.com/lh/photo/po1y3tPU99kA38VLMy2DOw?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/TIZejvMWL8I/AAAAAAAAAOE/kG2COZB3-gA/s400/IMG_20100906_171619.jpg" /></a>

And here is the left side rearset. The second pic is the backside showing the notch that had to be cut in the plate so the rearset wouldnt slip off the back and so i could have clearance between the plate adn the frame for the bolts to go.
<a href="http://picasaweb.google.com/lh/photo/w9dk15fK99cZARfgXUy0kA?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/TIZekmV7pUI/AAAAAAAAAOM/AiJyUx3wVm4/s400/IMG_20100906_171549.jpg" /></a>
<a href="http://picasaweb.google.com/lh/photo/M0FIq1fj1j-JsoIEfHAJ-g?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/TIZej7NV8-I/AAAAAAAAAOI/Nt1XMoMyuS8/s400/IMG_20100906_171604.jpg" /></a>

 

[rrredisk]

I finished up the right side rear set by mounting the master cylinder and parts to the bike. I also made a nice little exhaust bracket.

<a href="http://picasaweb.google.com/lh/photo/oonGnd1iW4sCxayn6smdkQ?feat=embedwebsite"><img src="http://lh3.ggpht.com/_1vpHzyxWSQs/TJjB3AnGRWI/AAAAAAAAAOg/QikiXPYR4Z8/s400/IMG_20100913_065816.jpg" /></a>

The bike is pretty much cosmetically done except for some scrubbing of the outside of the engine to give it a little shine. I will try to get some fancy pics of the bike one night this week. It is in decent running order but tends to backfire out the carbs and pods when the bike gets warm. I thought that this is usually caused by air getting in between the carbs and the engine by way of the boots some how. I have done the "spray with carb cleaner to listen for idle change" trick on all the boots and the idle doesnt seem to change at all when i spray in there. Anyone have any other possibilities of why it would backfire out the carbs. Its like a whisping pop sound, almost like air is getting shot back out the pods rather than getting sucked in, and it only really happens when the bike gets warmed up and at lower rpms. If I open up the throttle a bit it seems to run a bit better.

 

[MBS]

This build is coming along nice. Keep up the good work. -MBS

 

[rrredisk]

Tears were shed this past weekend with my bike. First off, i ended up getting home a good bit later than i usually do from work on friday. I got home with only a little bit of sunlight left so i decided to go wrench on the bike for a bit. I got my tools and went outside, only to find out that my ratchet had been busted and no longer worked. Turns out my room mate is a genius and thought it would be a good idea to use my ratchet as a hammer, rather than walk 10 steps and pick up the actual hammer i have... when i asked him to go get me another one to replace the one he broke he told me "it still works it just doesnt ratchet..." Well that kind of is the whole point behind owning a ratchet, is the fact that it ratchets... So after finding that out it put me in a crappy mood, then it went downhill from there. i walked out to the bike to notice that my petcock was leaking a little bit, so i took off the gas tank to get a better look at it. well there was apparently more gas in the tank than i expected because when i tilted the tank to look at the petcock, gas poured out the gas cap all down the side of the tank, instantly peeling off my clear coat on the tank, and leaving behind giant gummed spots of clear coat.

<a href="http://picasaweb.google.com/lh/photo/ShChg5uZ4ByGhBxwiievJw?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TKCxv8mi1dI/AAAAAAAAAPE/eIBQc707CNM/s400/IMG_20100925_112518.jpg" /></a>

it took me a solid 2 or 3 hours of carefully wetsanding the globs off as to not sand any of the blue paint below off. i finally got it looking decent and put several more layers of clear coat on to fill the clearcoatless hole. from about 5 feet away it looks good again, but when you move in closer you can see the spot where i had to patch.

<a href="http://picasaweb.google.com/lh/photo/jpsSzKDhoYTjW2z8f8V5Og?feat=embedwebsite"><img src="http://lh4.ggpht.com/_1vpHzyxWSQs/TKCxvY-O_1I/AAAAAAAAAPA/7G0xJewZQ8Q/s400/IMG_20100925_174116.jpg" /></a>

A plus for the weekend is that i finished up my side panels i made and mounted them to the bike. I also spent much of the day saturday cleaning up the engine with a wire brush and then painted the fins on the top end black. So even though the weekend was a frustrating one, i did get a few things done so its all good i suppose.

Left Side Panel
<a href="http://picasaweb.google.com/lh/photo/eOgkw4qDCKAxoK2rNiEtHQ?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TKCxtUqshYI/AAAAAAAAAO0/HC8M3B5oBDk/s400/IMG_20100926_153000.jpg" /></a>

Right Side Panel
<a href="http://picasaweb.google.com/lh/photo/2hsssbnTu8PaxmSlcZaieg?feat=embedwebsite"><img src="http://lh6.ggpht.com/_1vpHzyxWSQs/TKCxuJrVgCI/AAAAAAAAAO8/sJ2A5qEb7KY/s400/IMG_20100926_152941.jpg" /></a>

Painted Engine
<a href="http://picasaweb.google.com/lh/photo/EY63mon9FXeCR0sEr7s2cQ?feat=embedwebsite"><img src="http://lh5.ggpht.com/_1vpHzyxWSQs/TKCxtyX9FNI/AAAAAAAAAO4/Z1DL_dgW3aw/s400/IMG_20100925_174032.jpg" /></a>

 

[tWistedWheelz]

Man, you move along pretty fast!

The gauge cluster and all on the bike reminds me of the face of the short circuit robot!

"No disassemble Johnny number 5"


Keep up the work!

 

[rrredisk]

Man, you move along pretty fast!

The gauge cluster and all on the bike reminds me of the face of the short circuit robot!

"No disassemble Johnny number 5"


Keep up the work!

Haha, i never really thought about that, but it kinda does look like Number 5. I think you just gave me the name of my bike. up to this point i didnt really have a name for the bike, but i could change the numbers on the side panels to 5's and just name the bike "Number 5"

 

[IndieSol]

My bike (a 360 twin) is doing it as well. It only happens when it's idling, or at very low RPMs. I've started to foul plugs after city riding, but it will ride on the highway forever. As the plugs get dirtier doing city riding, the "pop" happens more frequently. I feel confident a carb cleaning will take care of it. I did that in June, and put in new float valves/needles, but ran with dirty air filters for a couple days before my new ones got in.

In my case, though, I plan on tearing the whole thing down in a week or two, so I just keep a spare set of clean plugs with me.